Method of and apparatus for frost elimination



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METHOD .or am APPARATUS roa mans,

FRO ST ELIIVHNATION Charles H.

Tanner and Ernest Watkins, St.

Cloud, Minn; Jessie M. Tanner administrator of said Charles H. Tanner, deceased Application June 2, 1934, Serial No. 728,783

9 Claims.

This invention relates .to the prevention and elimination of frost deposition in gas lines and more particularly to an apparatus and a method for eliminating frost in compressed air, natural and artificial gas as well as other gas lines.

In Patent No. 1,802,683 issued April 28, 1931 to one of us, a method is disclosed whereby deposition of frost in compressed airlines may be prevented. The present invention relates to an improved apparatus and method adaptab e for use in conjunction with gas lines of all kinds where-- in the gas contains some proportion of water vapor capable of depositing as frost upon a sufficient diminution in temperature.

I In the drawing:

Fig. 1 shows a side elevation with certain portions in section of one form of apparatus comprising the invention, and

Fig. 2 is a section in line II-II of Fig. 1.

Referring more particularly to the drawing, a line or main carrying gas, such as air, artificial or natural gas or other gas containing adventitious quantities of moisture. is shown generally at with means provided at 6 for admitting a vapor functioning to lower the temperature at which a given mixture of water vapor and other gas will deposit frost, as described more fully hereinafter.

For generating the frost preventing vapor, a liquid container I is provided of any desired type and size depending upon the quantity of materials to be contained, generally constructed of metal and provided at its upper portion 8 with the upwardly extending conduit 9. A tightly fitting cap l0 covers the upper end of conduit 9. removable upon removal of the locking device II. The upright conduit 9 serves as filling means for container 1 and a liquid substance in desired amount may be added to the container to the desired height. this height being determined by the sight glass i2 properly positioned upon the container, although other means for determining the level of the liquid in the tank may be used, as for instance, pet cocks placed at difierent heights upon the container and communicating with the interior thereof. In normal'operation the height of the liquid in the container is maintained some--' what below the upper confining portion 8 of the container to permit a vapor collecting and forming portion l3 between the surface I l of the liquid and the top 8 of the container I.

The line 9 is connected advantageously by means of a T l5 to the vapor introducing conduit i6 whereby vapors may be led from the top of the container into the gas line 5, 'a suitable checking valve ll being positioned in line IE to permit,fl0w of vapor from the container to the line..

A suitable heat exchanger is shown at l8 and may comprise any suitable form of heat exchanging apparatus such 'as the gas heater shown, although any other form of heating apparatus such as oil or electrical heating unit may be employed. Where the device of this invention is used in conjunction with artificial or natural gas lines, heat is provided in the heat interchanger by tapping the gas line as at l9 and leading the desired quantity of fuel through fuel line 20, regulated by valve 2|, to the burners 22 of the heat interchanger. Heat interchange is eifected by providing a coil 23 adjacent to the fuel burner of the heat interchanger, coil 23 being connected to and having fluid communication with feed line 24 attached to liquid container 1 adjacent the lower portion thereof and in general attached in such fashion that gravity feed may be had of the liquid contained in liquid container 1 to coil 23 of the heat interchanger. To effect gravity feed, l quid container! is advantageously elevated above the heater. Heating coil 23 and burner 22 are enclosed in a suitable housing 25 provided with oif- 20 take fiue 26 and a door 21 permitting. in the open position. access. to coil 23 and burner 22.

In order to drain spent liquid from liquid container I and from the coil 23 of the heat inter- I changer, a valved drain line 28 is provided ad- 30 jacent the lower portion of the system so that the system may be drained and cleaned at'periodic intervals or at such times as such draining and cleaning is necessary.

In order to form the completed system, return conduit 30 is attached to and'has fluid communi-' cation with the upper portion of coil 23 of the heat interchanger and leads to and has fluid communication with the vapor or upper portion l3 of liquid container 1. Thus upon inserting a material such as an aqueous solution containing a substantial portion of an alkaline substance such as calcium chloride, or other water soluble salts of metals of the alkali or alkaline earth group such as sodium, potassium, calcium, strontium or barium. or ammonium acetate. sodium acetate. or other alkali or alkaline earth acetate, mixed with an alcohol. into the liquid container to a height somewhat above the lower sight level 3| and below upper sight level 32, liquid tends to run into the heating coils. become heated and at the elevated temperature the escaping tendency of the alcohol in the mixture is increased, thereby increasing the vapor pressure of this material causing'rapid circulation of the heated substance haust line l6 into the gas main there to mix with gaseousmaterial containing moisture or water vapor.

By providing a disengaging space over the surface ll of liquid in container 1, unvaporized portions of liquid collect in the container and only the vaporized portion passes oif through line It to mingle with the gas in main 5. The vapor comprises alcohol and water vapor in small quantities which, when mixed with thewater vapor present in the gas, lower the frost point of the mixture to such an extent that such water-vapor is not removed as solid frost from the gas but remains therein in vapor" form and clogging of valves, pipes and connections with such frost is prevented. Or, where frost has already formed,

introduction of vapors formed as abovedescribed, causes the frost to pass into-vapor form or melt and free or open a line clogged with such frost. Fresh liquid may be introduced into container 'I thrpughline 9-asthe level I falls indicating consumption of the frost eliminating material.

Since in many-cases frost elimination of the type described are installed in isolated spots, an enclosure 33 of sufllcient size to enclose the heat interchanger l8 and container I is provided, preferably raised above the surface on the standards 34. The enclosure is provided with a suitable door 35 whereby entrance may be had to the inas line. Y

2.: In apparatus for eliminating frost in'gas" terior of the enclosure. Vents are provided in the top of the enclosure for the feed line 9 andflue 2B, and an opening,36 is formed in the bottom thereof in registry with burner 22 to supply air for combustion of fuel atburner 22.

' What is claimed is:

v 1. In apparatus for eliminating frost ingas lines, a gas line, a container for liquid. from which a vapor is generated for inclusion in the gas line, a heat interchanger adapted-to impart heat to the liquid, means for transporting liquid from the container to the heat interchange,- and separate means for conveying the liquid from the heat interchanger to the container, and means connecting the container and the gas line for conveying vapor from the liquid container to the lines, a-gas line, a container for. liquid from which a vapor is generated for inclusion in the gas line,- a heat-interchangeradapted to, im-

part heat .to the liquid, gravity conveying means connecting the container and. the heat interchanger for conveying liquid from the container ,to theheat interchanger, means for simultaneouslyconveying liquid and vapor from the heat interchanger to thegcontainer, and means connecting the container. and the gas line for conveying 'vapor from the liquid container to the gas line.-

-3. In apparatus for eliminating frost in gas lines; a gas line, a container for liquid from which a vapor is generated for inclusion in the gas line, means for determining the quantity of liquid in the container, a heat interchanger adapted to impart heat to the liquid, means for transporting liquid from the container to the heat interchanger, means for conveying liquid and vapor I from the heat interchanger to thecontainer, and

means connecting the container and the gas line for conveying vapor from the liquid container to the gas line.

4. In apparatus for, eliminating frost in gas lines, a gas line, a container for liquid from which a vapor is generated for inclusion into the gas line, a heat interchanger adapted to impart heat to the liquid, means for transporting liquid from the container to the-heat interchanger, means for conveying the liquid from the heat 'interchanger to the container, means connecting the container and the gas line for conveying vapor from the liquid container to the gas line,- and means for draining liquid from the container and heat interchanger. 3

5. In apparatus for eliminating frostin gas lines, a gas line, a container for liquid from which a vapor is generated for inclusion in the gas line, a heat interchanger adapted to impart heat to the liquid, means for transporting liquid from the container to the heat interchanger, means for conveying the liquid from the heat interchanger to the container, means connecting the container and the gas line for conveying vapor from the liquid container to the gas line, and

means enclosing said container and heat interchanger. I i i 6. In apparatus for eliminating frost in gas lines carrying combustible gas, a gas main, a container for liquid from which a vapor is generated for inclusion into the gas line, a heat interchanger adapted to impart heat to the liquid, means for transporting liquid from the container to the heat interchanger, means for conveying the liquid from the heat interchanger to the container, means'connecting the container and the gas line or conveying vapor from the liquid container to. the gas line, and means connecting the gas main and heat interchanger for supplying the heat interchanger with combustible gas for combustion therein to impart heat thereto.

7. In apparatus for eliminating frost in gas lines, a gas line, a container for liquid from which a vapor is generated for inclusion in the gas line, a heat interchanger adapted to impart heat to the liquid, means for transporting liquid from the container to the heat interchanger, means .for conveying the liquid from the heat inter- 'means for transporting liquid from the container to the heat interchanger, and separate means for conveying the liquid from the heat interchanger to the container, and means for connecting the container and the gas line for conveying vapor from the liquid container to the ga shne.

9.- In apparatus for-eliminating frost in gas lines, a gas line, a container for liquid from which a vapor is generated for-inclusion in the gas line, means for heating the liquid to raise the vapor pressure of the liquid, means for diverting a portion of the gas in the gas line to said heating means to provide operating fuel therefor, and means connecting the container and the gas line for conveying vapor from the liquid contalnerto the gas line.

CHARLES H. TANNER. ERNEST WATKINS. 

